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Food, Livestock, Energy, Climate, And Health

by 5m Editor
14 September 2007, at 11:49am

GLOBE - Food provides energy and nutrients, and its acquisition requires the expenditure of energy. In post-hunter-gatherer societies, with progressively increasing inputs of extra-somatic energy, the scale of catching, gathering, and producing food has been greatly expanded and methods intensified.

Today, relations between energy, food, and health have become complex and multifaceted, raising serious policy concerns at national and international levels.

Substantial and widespread public-health problems of under-nutrition and over-nutrition exist—often coexisting within the same population. Meanwhile, the world's agricultural sector, especially livestock production, accounts for about a fifth of total greenhouse-gas emissions, thus contributing to climate change and its effects on health, including on regional food yields. Policy responses to the connections between food production, energy, climate, and health should include countering the world's rapidly increasing consumption of meat, which poses health risks by exacerbating climate change and by direct contribution to the causation of certain diseases. These linkages are explored in this paper, and recommendations for policy are made.

The story of world food production and associated changes in population health over recent centuries comprises both good and bad news. There is much good news: food production capacity has increased greatly; maternal and child nutrition in high-income populations and groups has improved; health and life expectancies have increased, at least partly because of nutritional gains; and refrigeration, transport, and open markets have increased year-round access to healthy foods for many populations.

Meanwhile, health risks are also accruing: the expansion of food production is depleting land cover and biodiversity, with diverse consequences for human wellbeing and health; major elemental cycles are being disrupted (eg, fertiliser use has vastly increased the concentration of bioactive nitrogen compounds in the global environment); industrial food refining, marketing, and over-consumption increase the risks of some non-communicable diseases; and fossil fuel inputs to modern food systems, together with other aspects of crop production and animal husbandry, contribute substantially to greenhouse-gas emissions.

Key messages

  • Greenhouse-gas emissions from the agriculture sector account for about 22% of global total emissions; this contribution is similar to that of industry and greater than that of transport. Livestock production (including transport of livestock and feed) accounts for nearly 80% of the sector's emissions
  • Methane and nitrous oxide (which are both potent greenhouse gases and closely associated with livestock production) contribute much more to this sector's warming effect than does carbon dioxide
  • Halting the increase of greenhouse-gas emissions from agriculture, especially livestock production, should therefore be a top priority, because it could curb warming fairly rapidly. However, livestock production is projected, on current trends, to increase substantially over the next four decades, mainly in countries of low or middle income
  • Available technologies for reduction of emissions from livestock production, applied universally at realistic costs, would reduce non-carbon dioxide emissions by less than 20%. We therefore advocate a contraction and convergence strategy to reduce consumption of livestock products, mirroring the widely supported strategy proposed for greenhouse-gas emissions in general. Contraction of consumption in high-income countries per head would then define the lower, common, ceiling to which low-income and middle-income countries could also converge
  • Assuming a 40% increase in global population by 2050 and no advance in livestock-related greenhouse-gas reduction practices, global meat consumption would need to fall to an average of 90 g per person per day just to stabilise emissions from this sector. Such a decrease would require a substantial reduction of meat consumption in industrialised countries and constrained growth in demand in developing countries, especially of red meat from ruminant (methane-producing) animals
  • A substantial contraction in meat consumption in high-income countries should benefit health, mainly by reducing the risk of ischaemic heart disease (especially related to saturated fat in domesticated animal products), obesity, colorectal cancer, and, perhaps, some other cancers. An increase in the consumption of animal products in low-intake populations, towards the proposed global mean figure (convergence), should also benefit health
  • The resultant gains in health and environmental sustainability should help to offset any (initial) discomforts from restrictions on some popular foods and altered dietary customs. Replacing ruminant red meat with meat from monogastric animals or vegetarian-farmed fish would reduce methane production and lower the pressures on wild fisheries as sources of fishmeal for aquaculture
  • Climate change will, itself, affect food yields around the world unevenly. Although some regions, mostly at mid-to-high latitude, could experience gains, many (eg, in sub-Saharan Africa) are likely to be adversely affected, with impairment of both nutrition and incomes. Compensating vulnerable populations for this and other climate-mediated harm caused by other populations should be an important element of global climate change policy
  • Global population growth is continuing, although slowing. The eventual peak size is not predetermined: it can be lowered by education, leadership, and wider contraceptive availability. Slower population growth will help achieve the Millennium Development Goals and will limit population size, climate change, and the environmental effects of food production

Further Reading

- You can view the full article by clicking here.


Source: TheLancet

5m Editor